The Border Security Force - responsible for guarding against extremists, drug and weapons smugglers and human traffickers - is using its muscle to detain, torture and kill with impunity, according to the 81-page report released by the New York-based rights group.

While authorities say the suspects were killed in self-defense or for evading arrest, Human Rights Watch said it “found no evidence in any death it documented that the person was engaged in any activity that would justify such an extreme response.”

“The border force seems to be out of control, with orders to shoot any suspect,” said the organization’s South Asia director, Meenakshi Ganguly, in a statement.

The group said it based its findings on more than 100 interviews with victims, witnesses, activists, journalists and border guards from both India and Bangladesh. The border force denied the allegations.

The guards “only fire when they are attacked,” and most shootings occurred at nighttime when smugglers and looters operate, said C.V. Muralidhar, inspector general for the South Bengal Frontier, one of several border areas. He said when there is an infraction, “the punishment is very harsh.”

Bangladesh said, however, it has long been concerned with the situation and is discussing with India the possibility of guards using weapons other than firearms.

“We always request the Indian government not kill our people along the border whatever the cause is,” said Abdus Sobhan Shikder, head of the Home Affairs Ministry. “But the people on the ground sometimes overstep.”

Many of the 900 Bangladeshis killed over the last decade were poor farmers or laborers taking cattle illegally across the border for trade, the report says. Some were hit by scattered cross-border firing or killed without due cause, such as 13-year-old Abdur Rakib, killed while catching fish in a lake on the Bangladeshi side.

A 15-year-old wounded in the same hail of bullets that killed Rakib described the incident to Human Rights Watch.

“I had taken our three buffaloes for grazing in the field,” Mohammad Omar Faruq is quoted as saying. “A BSF soldier was standing at the border and loudly talking to the boy who was catching fish. It seemed that he wanted the boy to give him some free fish.”

Faruq said the two began insulting each other and the guard pulled out a gun. “The boy ran and the soldier started to shoot. ... I was hit on the right hip and fell down.”

Another Bangladeshi quoted in the report said he was tortured after straying across the border while cutting grass. He said the border guards blindfolded him, took him to a camp and tied him to a tree for a day. “I was beaten severely with a bamboo stick on my back and feet. ... The BSF men jumped on my chest, and kicked me on my head and face with their boots,” he said.

Despite hundreds of abuse complaints by both Indians and Bangladeshis, few cases have been registered by local police and no guards have been prosecuted, the report said.

“This sends a clear message that the Indian government finds such abuses acceptable,” the report said, urging both Bangladesh and India to investigate the situation. The border force assured it was conducting internal investigations, but would not say if anyone has been punished, according to the report.

The porous and patchy border was carved in the 1947 partition between India and East Pakistan, which became independent Bangladesh in 1971. Security has tightened against smugglers as well as citizens visiting relatives and impoverished immigrants looking for better economic opportunities.

Indian border officials say their Bangladeshi counterparts do not do enough to prevent illegal cross-border smuggling. Cattle rustling in particular is rife, with 51,900 heads of cattle seized so far this year, the border force said.

A frequent target of militant attacks, India is also edgy about extremists infiltrating and recently started building a floodlit fence of concrete and barbed wire along parts of the 2,500-mile (4,000-kilometer) border.

“The border force, with a peacetime mission of preventing illegal activity, is acting like it is in a war zone, torturing and killing local residents,” Ganguly said.